iOS masonary 约束 做动画

    [UIView animateWithDuration:0.1 animations:^{
        [self.tipImage mas_updateConstraints:^(MASConstraintMaker *make) {
            make.bottom.equalTo(popView.mas_bottom).offset(-(kRatio(54)+BottomHeight));
        }];
        [self.view layoutIfNeeded];/// 一定调用 控件的父view layoutIfNeeded
    } completion:^(BOOL finished) {
    }];